AI clouds: the buyers

Five companies, one decision

The AI build-out is, financially, the decision of a handful of companies. Microsoft, Amazon, Alphabet, Meta and Oracle reported $566B of capital spending over their latest four quarters, up from $184B two years earlier. Not all of it is for AI, and none of them splits the figure out, but their filings attribute the growth to AI and cloud infrastructure, and the suppliers’ revenue confirms where it went.

Treat these companies as two kinds of buyer. Microsoft, Amazon, Alphabet and Oracle rent capacity to others, so their spending is a bet that customers will pay for it through their cloud businesses. Meta builds for its own apps, so its return shows up in advertising: better ranking, better ad targeting and the products it hopes to build on its own models. The first kind can point to cloud revenue as the return. The second has to argue it from engagement and ad pricing, which is harder to see from outside.

Together they earn $1.91T of revenue, +35% in two years, at an operating margin of 27%. That revenue is mostly not AI: it includes Amazon’s shop, Alphabet’s search ads, Microsoft’s Office and Windows. The point of listing it is scale. These companies can afford the spending; the question is how long they will want to, and what it does to their returns on capital.

From spare cash to all of the cash

The most important number on this page is the ratio of capex to operating cash flow. It bottomed at 35% in Q3 2023 and reached 97% in Q2 2026. At a third, the build-out is an expense these companies fund from spare cash while still buying back stock. At nearly all, it competes with buybacks and dividends for every dollar, and any further growth must come from the balance sheet.

Company by company the margin of safety differs. Microsoft spent $136B against $196B of operating cash flow; Alphabet $160B against $180B. Amazon spent $173B against $161B, and Meta $104B against $133B. Oracle spent $75.7B against $46.9B: like Amazon, it spends more than its business generates, and by the widest margin, so it is the one to watch for the cost of funding.

Capex also understates the commitment. Microsoft, Meta, Oracle and Alphabet disclose $1.08T of data-center leases they have signed that haven’t started yet. Those payments will run for 15 to 20 years or more, and they don’t appear in capex or on the balance sheet until the buildings are ready. Following the money adds them up.

The return is the cloud businesses

If the spending pays, it pays through the cloud segments. AWS earned $148B of revenue over its latest four quarters, +28%, and $54.7B of operating income. Google Cloud earned $93.2B, +76%, and its operating income rose +198% to $31.8B. Microsoft Cloud, which also includes Microsoft 365 and Dynamics, brought in $229B. Oracle’s cloud infrastructure, the fastest-growing of them from a smaller base, reached $22.1B, +94%.

Two things in these numbers are encouraging. Growth has accelerated at every one of them over the past year, which is what you would expect if new capacity is being sold as it comes online. And operating income is growing at least as fast as revenue, which means the depreciation of the new equipment is being absorbed so far. The concern is the gap in scale: the clouds’ combined revenue is still well short of the buyers’ combined capex, and the depreciation of this year’s spending has barely started.

Backlog is the other evidence. Oracle reports $664 billion of remaining performance obligations and expects to recognize about 13% of it in the next twelve months. Microsoft reports $683B, Alphabet $568B. A backlog that large is demand made contractual, but it is only as good as the customers behind it, and several of the largest are AI labs funded by investors rather than by profits.

The GPU-only clouds

CoreWeave and Nebius are the purest listed bets on renting AI capacity. CoreWeave reported $7.6B of revenue over its latest four quarters, +115%, while spending $20.6B on equipment, 2.7× its revenue. Its backlog is $104B. The model is to sign long contracts with large customers and borrow against them to buy GPUs, so the business is as strong as its contracts and its access to credit.

Concentration is the risk to understand. CoreWeave reported that Microsoft accounted for about two-thirds of its 2025 revenue, and its largest new contracts are with OpenAI and Meta. Nvidia is both its sole GPU supplier and a shareholder. Nebius, which files a 20-F, reported $530M of revenue for 2025 and $4.1B of capex. These companies grow fastest when capacity is scarce; their test comes when it isn’t.

Cloudflare is a different kind of AI cloud. Rather than renting whole GPU clusters for training, it runs inference on GPUs spread across its global network, close to the users making requests. It reported $2.5B of revenue over its latest four quarters, +34%, at a 73% gross margin, while spending only $285M on capex. If more AI work shifts from training giant models to answering requests quickly, networks built for the edge are the part of this layer positioned for it.

What would change the picture

The bull case for this layer is simple: AI demand is real, the clouds are selling capacity as fast as they build it, and the businesses that own the most capacity will earn the most when demand matures, as they did in the first cloud cycle. The cloud segments’ accelerating growth and rising operating income support it.

The bear case is about returns on capital rather than demand. If capex keeps growing faster than cloud revenue, depreciation will compress margins even as revenue grows, and the stocks would be paying for growth that earns less than it used to. Watch for the moment capex guidance flattens. It will show whether the buyers think the capacity they have is enough, and it will hit every supplier layer below at once.

The companies, side by side

Latest four reported quarters for US filers; latest fiscal year for 20-F filers (marked). Underlined names have their own company page; the others link to the company’s filings on SEC EDGAR. Margins are left blank where a company doesn’t report gross profit or cost of revenue.

Where the money comes from and goes

This layer is paid by software. Its own spending flows to servers, networking, power & DCs, chips. For the dollar amounts and who keeps them, see following the money.

Financing links that involve this layer

Quoted from the filings. Numbers match the money-loop map.

• 1Microsoft → OpenAIEquity investment

  $11.9B funded of $13.0B committed

  “We have made total funding commitments of $13.0 billion related to our investment, of which $11.9 billion has been funded as of June 30, 2026.”

  Microsoft 10-K for the period ended June 30, 2026, filed July 29, 2026

• 2OpenAI → MicrosoftReported revenue

  $24.1B of Microsoft revenue in FY2026

  “For fiscal year 2026, we recorded revenue from commercial arrangements with OpenAI, inclusive of revenue-sharing payments, of $24.1 billion, and accounts receivable from OpenAI as of June 30, 2026 was $6.0 billion.”

  Microsoft 10-K for the period ended June 30, 2026, filed July 29, 2026

• 3Amazon → AnthropicEquity investment

  $8.0B in convertible notes, 2023–2025

  “From Q3 2023 to Q4 2025, we invested $8.0 billion in convertible notes from Anthropic, which are classified as available-for-sale and reported at fair value with unrealized gains and losses included in "Accumulated other comprehensive income (loss)" and as Level 3 assets.”

  Amazon 10-Q for the period ended June 30, 2026, filed July 31, 2026

• 4Amazon → AnthropicEquity investment

  $5.0B in Series G preferred, 2026

  “In Q2 2026, we invested $5.0 billion in Anthropic Series G nonvoting preferred stock.”

  Amazon 10-Q for the period ended June 30, 2026, filed July 31, 2026

• 5Amazon → AnthropicCredit or guarantee

  Up to $20B facility, released as compute is delivered

  “Additionally, we entered into a financing arrangement to make available to Anthropic an aggregate facility not to exceed $20.0 billion that will expire 30 months after an Anthropic liquidity event, including an initial public offering ("IPO").”

  Amazon 10-Q for the period ended June 30, 2026, filed July 31, 2026

• 6Anthropic → AmazonPurchase commitment

  Commitment to AWS expanded by more than $100B over 10 years

  “In Q2 2026, AWS and Anthropic announced an expansion of the strategic collaboration and existing multi-year commitment by more than $100.0 billion over 10.0 years, which includes contractual obligations related to the performance of AWS chips.”

  Amazon 10-Q for the period ended June 30, 2026, filed July 31, 2026

• 7Amazon → OpenAIEquity investment

  $50B of preferred stock: $15B invested, $35B committed

  “We also invested $15.0 billion in Series C Preferred Stock of OpenAI and entered into an equity commitment letter agreement (the "Letter Agreement"), pursuant to which we agreed to purchase additional shares of Series C Preferred Stock (the "Commitment Shares") with an aggregate purchase price of $35.0 billion (the "Commitment Amount").”

  Amazon 10-Q for the period ended June 30, 2026, filed July 31, 2026

• 8OpenAI → AmazonPurchase commitment

  $38B AWS commitment, expanded by $100B over 8 years

  “In Q1 2026, AWS and OpenAI Group PBC ("OpenAI") announced an expansion of the existing $38.0 billion multi-year commitment and commercial arrangement with OpenAI by $100.0 billion over 8.0 years, which includes contractual obligations related to the performance of AWS chips.”

  Amazon 10-Q for the period ended June 30, 2026, filed July 31, 2026

• 9Amazon → AnthropicEquity investment

  $5.0B in Series H preferred, drawn from the facility

  “Under this financing arrangement, in Q2 2026, we exercised our option to participate in subsequent Anthropic equity financings by investing $5.0 billion in Anthropic Series H nonvoting preferred stock, which reduced the amount available under the facility to $15.0 billion.”

  Amazon 10-Q for the period ended June 30, 2026, filed July 31, 2026

• 10OpenAI → CoreWeavePurchase commitment

  Up to $11.9B through October 2030 (first agreement)

  “For example, in March 2025, we entered into a master services agreement with OpenAI, a private company, pursuant to which OpenAI has committed to pay us up to approximately $11.9 billion through October 2030.”

  CoreWeave 10-K for the period ended December 31, 2025, filed March 2, 2026

• 15Nvidia → CoreWeaveEquity investment

  $2.0B share purchase, January 2026

  “In January 2026, we entered into a securities purchase agreement with NVIDIA Corporation for a private placement of approximately 23 million shares of our Class A common stock at a purchase price of $87.20 per share, for aggregate gross proceeds of $2.0 billion.”

  CoreWeave 10-Q for the period ended June 30, 2026, filed August 12, 2026

• 16Microsoft → CoreWeaveReported revenue

  67% of CoreWeave’s 2025 revenue

  “We recognized an aggregate of approximately 67% of our revenue from our top customer, Microsoft, for the year ended December 31, 2025.”

  CoreWeave 10-K for the period ended December 31, 2025, filed March 2, 2026

• 17Meta → CoreWeavePurchase commitment

  Up to $21.0B through 2032

  “Similarly, in March 2026, we entered into an order form under an existing master services agreement pursuant to which Meta Platforms, Inc. ("Meta") initially committed to pay us up to approximately $21.0 billion (inclusive of access to new computing capacity through December 20, 2032 and the exercise of an existing option to access additional computing capacity through April 10, 2032) and, as a result, we also expect Meta to be a significant customer in future periods.”

  CoreWeave 10-Q for the period ended June 30, 2026, filed August 12, 2026

• 18OpenAI → CoreWeavePurchase commitment

  Up to $6.5B through May 2031 (one order form)

  “In May 2025, we entered into a master services agreement with OpenAI OpCo, LLC ("OpenAI") and in September 2025, we entered into an order form under this master services agreement pursuant to which OpenAI committed to pay us up to approximately $6.5 billion through May 31, 2031 and, as a result, we expect OpenAI to be a significant customer in future periods.”

  CoreWeave 10-Q for the period ended June 30, 2026, filed August 12, 2026

• 20AMD → MetaCustomer warrant

  Warrant for up to 160M AMD shares at $0.01

  “In October 2025 and February 2026, the Company issued warrants to OpenAI OpCo, LLC (OpenAI) and Meta Platforms, Inc. (Meta), each entitling the holder the right to purchase up to 160 million shares of the Company’s common stock at an exercise price of $0.01 per share (the OpenAI Warrant and the Meta Warrant, respectively).”

  AMD 10-Q for the period ended June 27, 2026, filed August 5, 2026

• 21HPE → OracleCustomer warrant

  Warrant for up to 4.2M HPE shares, tied to networking in Oracle’s AI data centers

  “The Warrant was issued in connection with the Holder entering into a strategic collaboration with the Company to deploy the Company’s networking solutions in the Holder’s AI data centers.”

  HPE 10-Q for the period ended July 31, 2026, filed September 3, 2026

• 22Meta → Meta’s data-center venturesCredit or guarantee

  $41.5B of residual value guarantees, $68.4B maximum exposure

  “The following table summarizes our maximum exposure to loss in the unconsolidated data center ventures (in millions): September 30, 2026 December 31, 2025 Carrying value of equity investments $4,732 $1,826 Lease commitments 18,476 12,311 Future funding commitments 3,703 3,724 Maximum residual value guarantees 41,493 28,091 Total $68,404 $45,952 Other In addition, we have other types of unconsolidated VIEs of which we are not the primary beneficiary.”

  Meta 10-Q for the period ended September 30, 2026, filed October 22, 2026

• 23Meta → Third-party cloudsPurchase commitment

  $454.5B of non-cancelable commitments, mostly cloud capacity

  “As of September 30, 2026, we had $454.52 billion of non-cancelable contractual commitments, comprising both short-term and long-term arrangements, most of which are related to third-party cloud capacity arrangements and other investments in technical infrastructure, and we continue to enter into additional significant contractual arrangements.”

  Meta 10-Q for the period ended September 30, 2026, filed October 22, 2026

• 24Microsoft → ConstellationPower contract

  20-year PPA for a restarted nuclear plant

  “The restart is supported by a 20-year PPA with Microsoft to purchase the output generated from the renewed plant.”

  Constellation 10-Q for the period ended June 30, 2026, filed August 6, 2026

• 25Meta → VistraPower contract

  2,609 MW of nuclear power under 20-year PPAs

  “In January 2026, Vistra announced it had entered into 20-year PPAs with Meta, pursuant to which the Company has agreed to supply Meta with a total of 2,609 MW of carbon-free power and capacity from the Company's PJM nuclear power plants as follows: 1,268 MW of energy and capacity from Perry and 908 MW of energy and capacity from Davis-Besse; and 213 MW of uprate energy and capacity from Perry, 80 MW of uprate energy and capacity from Davis-Besse, and 140 MW of uprate energy and capacity from Beaver Valley.”

  Vistra 10-Q for the period ended June 30, 2026, filed August 10, 2026

What to watch in the next filings

• Capex guidance on each quarterly call, and the capex-to-operating-cash-flow ratio in each 10-Q.
• Cloud segment growth and operating margin: AWS, Google Cloud, Microsoft’s Intelligent Cloud, Oracle’s cloud infrastructure.
• Changes in server useful lives. A shorter life means more depreciation and lower earnings.
• Debt issuance and credit spreads at Oracle and CoreWeave, the buyers furthest past self-funding.
• Leases signed but not yet started, and when they begin.